Ionic polymer metal composite(IPMC)is a new kind of ionic electroactive polymer.Large deformation is generated when low voltage supplied on IPMC.IPMC is a good choice for biomimetic driving materials because of its good flexibility、fast response、working without noise and the characteristic like human muscle.In this paper the blocking force of IPMC is tested and the IPMC test system is built based on NI PXI virtual instrument platform.The acquisition and analysis data software is written through Labview,and the blocking force characteristic variation of IPMC could be read clearly.The IPMC manufactured by commercial film and casting film are test,the law of variation of IPMC under different voltage is studied.